/*
 * Copyright (c) 1999, 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.main;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StreamTokenizer;

import com.sun.tools.javac.util.ListBuffer;

/**
 * Various utility methods for processing Java tool command line arguments.
 * 
 * <p>
 * <b>This is NOT part of any supported API. If you write code that depends on
 * this, you do so at your own risk. This code and its internal interfaces are
 * subject to change or deletion without notice.</b>
 */
public class CommandLine {
	/**
	 * Process Win32-style command files for the specified command line
	 * arguments and return the resulting arguments. A command file argument is
	 * of the form '@file' where 'file' is the name of the file whose contents
	 * are to be parsed for additional arguments. The contents of the command
	 * file are parsed using StreamTokenizer and the original '@file' argument
	 * replaced with the resulting tokens. Recursive command files are not
	 * supported. The '@' character itself can be quoted with the sequence '@@'.
	 */
	public static String[] parse(String[] args) throws IOException {
		ListBuffer<String> newArgs = new ListBuffer<String>();
		for (int i = 0; i < args.length; i++) {
			String arg = args[i];
			if (arg.length() > 1 && arg.charAt(0) == '@') {
				arg = arg.substring(1);
				if (arg.charAt(0) == '@') {
					newArgs.append(arg);
				} else {
					loadCmdFile(arg, newArgs);
				}
			} else {
				newArgs.append(arg);
			}
		}
		return newArgs.toList().toArray(new String[newArgs.length()]);
	}

	@SuppressWarnings("static-access")
	private static void loadCmdFile(String name, ListBuffer<String> args)
			throws IOException {
		Reader r = new BufferedReader(new FileReader(name));
		StreamTokenizer st = new StreamTokenizer(r);
		st.resetSyntax();
		st.wordChars(' ', 255);
		st.whitespaceChars(0, ' ');
		st.commentChar('#');
		st.quoteChar('"');
		st.quoteChar('\'');
		while (st.nextToken() != st.TT_EOF) {
			args.append(st.sval);
		}
		r.close();
	}
}
